1. Field of the Invention
The present invention relates to an identifying apparatus, an apparatus to be identified, an identifying method and a printing apparatus, suitable for the use of monitoring consumables of a product including a consumable that can be exchanged, for example, a copying machine, a printer or a facsimile apparatus.
2. Description of the Related Art
In general, consumables, such as toner, are used in a copying machine and a printer. For ease of maintenance by the user, consumables are unitized to allow easy exchange.
Such a consumable unit usually deteriorates through usage. Therefore, when the amount of the consumable in the unit reaches a certain level, the consumable unit cannot offer initial performance. To prevent this, conventionally, the apparatus main body monitors the amount of the consumable in the unit; and when the consumable unit approaches the end of its lifetime, a measure of prohibiting the use of the unit is taken.
However, the amount of the consumable in the unit is generally monitored as the number of sheets printed from the time when the consumable unit is attached. Therefore, even if a used consumable unit is attached, the consumption will be monitored as an unused unit. Thus, there is a problem that a used consumable unit or a consumable unit fabricated by using a used unit as a base can be used as a new unit.
There is a consumable unit with a memory, so that the consumption of the consumable unit is stored in the memory. However, in this case, there is a problem that it can easily be counterfeited as a new unit by rewriting the memory.
Further, there is a system in which, when a consumable unit is attached to the apparatus main body, a part of the consumable unit is mechanically or electrically broken, so that new and used units can be distinguished. However, with this structure, it is difficult to recycle the unit in the regular route.